The P-ROC / P3-ROC (and their related driver boards) are a set of pinball machine controller boards that allow a computer running custom software to control a pinball machine. The P-ROC board is an intelligent interface board that controls the low level pinball machine circuitry according to instructions from the computer running the game code. In most cases, a single-board computer works quite well as the computer. The P-ROC board can be used to either (1) replace the CPU board on existing machines (WPC-x, Stern Whitestar, or Stern S.A.M. systems) so they can run custom software, or (2) control a new pinball machine, whereas a P3-ROC can be used only to control new machines.